Carburetor



Feb. 19, 1935. w. JOHNSON 1,991,804

GARBURETOR Filed Feb. 1. 1933 K .Zkveniar':

Ax/12 2, ZZMM/ $27M [Xian-407K Patented Feb. 19, 1935 PATENT OFFICECARBURETOR William Johnson, Charleville, Queensland, Ans tralia,assignor toJohnsons Burner Proprietary Limited, Brisbane, Queensland,company of Queensland,- Australia Australia, a

Application February 1, weasel-m1; 0.654333 :In Australia November 3,1932 j Claims (01.261 50) This invention relates to animprovedcarburetor and refers more particularly to a. carburetor for use withinternal combustion engines.

The object of the invention is tozp'rovide a 5 carburetor which. will beefficient, and enable better carbureti'on with a relatively low fuelconsumption, provision being made iwhereby fuels having differentboiling points, such as petrol and kerosene, maybe individually used atwill; and

whereby the carburetor. will, function for air 'braking whenso desired.

'In order thatthe invention may be better understood reference will bemade to the accompanyingdrawing wherein V Figure 1 is a part sectionalside elevation of a carburetor according to this invention; Figure '2 isan'end elevation of the same Figure 3is a part "sectional elevation ofthe fuel valve assembly? 1 Y Figure 4' is a detail view of the ilapvalve; and Figure 5 is a detail'view of thefuel valve; and Figure 6 isan enlarged fragmentary sectional detail view of the primary mixingchamber.

Referring to the drawing, the air tube Axis right angled and providedwith a flange 'A for securing it to the induction. manifold of aninternal combustion engine. A block C upon which the fuel valve assemblyismounted is. provided. Immediately below the valve assembly a flapvalve 00 D is hinged at its upper edge to the inside topof the air tube,said flap valve D being connected to the valve F by a. link E. Link E isconnected to valve F as shown in Fig. 5 and extends-downwardly loopingat E" and is connected to valve D i so that as valve D swings about itspivot B the behind the flap 'valve D. The link E is given a turn atEwhich affords a certain amount of restrained motion bctwcen the flapvalve, D and the valve F. As shown in the drawing the tube K opens intothe block C and receives air from the air tube A. This is onlynecessary, as a precautionagainst foreign matter entering the valvechamber.- A filter may. be positioned in the inlet end of tube K.

. The fuel, either petrol or kerosene, is led into the fuel valvechamber by pipe K2 from a suitable cook or cocks operated by lever L. Todampen any sudden shocksupon the flap valve D andgive a restrainedaction to it, a cylinder N is mounted at the rear of the 'air tube A andit houses a spring C which rests upon a piston M-connected 5 by rod M tothebottom edge of flap valveDa A very small hole M2 is provided in thepistonrM to allow air to pass :during thestrokes as the-flap valve D isswinging. f V

The heavy flap P, hinged atits lower edge in 10 the bend of the air tubeA, normallyat its upper edge lies upon the upper bend. of the tube A,and closes the tube (as shown in" Figure 1). The weight'of this fiap'Pmay be varied for different modifications of the invention and resultsdesired. v1 v, A set screw Q is mounted at the back of the valve P andis adapted to be set to .prevent the backward movement past thepositionset, thus proprovided for controlling the amount of the mixtureto be admitted to the induction pipe.

In use. when the engine is being started up. the 5 cock L will be set todeliver petrol to, the valve F; the flap valve D will be swung back byentube K and thence to the -air tube-A posterior to theflapvalve D.After the engine has warmed up sufficiently the cock'L may be turned toclose the petrol line and open the kerosene line. I .30 It Will be seenthat the. quantity of petrol or otherfuel delivered is governedprimarily by the flap valve D; as it opens and shuts it opens and shutsthe said V-shaped opening G allowing various quantities of fuel to passto the mixing -45 chamber V. As the valve D swings it is restrained bythe piston M, and as a furtheradjustment the spring 0 may be compressedby turning the screw cap N down on the spring 0 in cylinder N.

Withidifierent' engines and different fuels it may be desirable toadjust the proportionscof the mixture entering the induction pipe.

The, rate of flow of petrol or other fuel to bejdelivered by the valveF, as before stated, is governed by the opening and closing of theV-shaped hole G, which is operated automatically by the flap valve .1).A means of altering the rate of flow is provided by the knurled nut Twhich turns loosely upon the hollow stud U (which screws into the blockC). The knurled nut T is internally threaded and adapted to screw up ordown upon the valve chamber J thereby, asmay be desired, slightlyraising or lowering its relative position to the valve tube F andaltering the position of gine' stops running and the flap valve D comesto rest it automatically closes the opening G and brings the shoulderinto contact with seating H thereby effectually shutting off the fuelsupply. To facilitate the opening of the fuel valve F, when idling (andwhen. the suction is not sulficiently strong to raise flap valve D) anair duct W may be provided and may consist of a tube leading from abovethe butterfly valve to a position in the cylinder ahead of the piston M.When idling the butterfly valve R is nearly closed and the suction uponthe duct W is greatest and tends to create a partial vacuum in thecylinder N behind piston M which allows flap valve D to swing back andopen the fuel valve F to a greater degree. Upon increase of engine speedthe piston M will pass back over the opening of the said duct W and makeit inoperative.

When it is desired to employ the invention for braking purposes (as whendescending an incline) the pipe lines from the fuel supply tanks are allsimultaneously closed by turning the cock L into a neutral positionthereby allowing any desired quantity of air permitted by the butterflyvalve R to pass along the tube A to the induction manifold and thence tothe cylinders.

1. A carburetor comprising a right-angled air tube, having vertical andhorizontal legs, open at one end and adapted to be connected at theother end to an intake manifold of an internal combustion engine, a fuelvalve assembly mounted on the upper portion of the horizontal leg of theair tube, said valve assembly comprising a tubular valve casing open atits top, provided with a portion of enlarged diameterconstituting amixing chamber'and having a valve seat formed therein, a hollow tubularvalve body positioned in said casing, said valve body being open at itsupper end and provided with an enlarged closed bottom portion adapted toengage said seat, said tubular valve body having opposed V-shapedopenings formed in the walls thereof immediately above the enlargedbottom portion, a flap valve in the air tube located beneath the saidfuel valve assembly and hinged at its upper edge, a link between saidflap valve and the fuel valve for opening and closing the fuel valve asthe flap valve swings, a tube connecting one side of said fuel chamberwith the air tube on the anterior sideof said flap valve, and a tubeconnecting the other side of said fuel chamber with the air-tube on theposterior side of the flap ialve.

2. A-carburetor comprising a right-angled air tube, having vertical andhorizontal legs, open at one end and adapted to be connected at theother end to an intake manifold of an internal combustion engine, a fuelvalve assembly mounted on the upper portion of the horizontal leg of theair tube, said valve assembly comprising a tubular valve casing open atits top, provided with a portion of enlarged diameter constituting afuel chamber and having a valve seat formed therein, a hollow tubularvalve body positioned in said casing and movable therein, said valvebody being open at its upper end and provided with an enlarged closedbottom portion adapted to engage said seat, said tubular valve bodyhaving opposed V-shaped openings formed in the walls thereof immediatelyabove the enlarged bottom portion. a flap valve in the airtube locatedbeneath the said fuel valve assembly and hinged at its upper edge; alink between said flap valve and the fuel valve for opening and closingthe fuel valve as the flap valveswings, a tube connecting one side ofsaid fuel chamber with the air tube on the anterior side of said flapvalve, a tube connecting the other side of said fuelchamber with the airtube on the posterior side of the fiap'valve, and means for adjustingthe opening of the valve irrespective of the action of the flap valvecomprising an'interiorly threaded member rotatably mounted in the upperportion of the air tube body and threadedly engaging the tubular valvecasing for vertically adjusting thetubular valve casing relativeto thevalve body.

3. An improved carburetor consisting of a right-angled air tube havingvertical and horizontal legs open at one end and adapted for connectionto an intake manifold at the other, a fuel valve assembly upon thehorizontal leg of the air tube, a flap valve in the air tube locatedbeneath the said fuel valve assembly and hinged at its upper edge, alink between said flap valve and the fuel valve for opening andclosingthe fuel valve as the flap valve swings, a butterfly valve in thevertical leg of the air tube operable by the driver, means for enablingvariation bend of the tube and adapted to normally close the passage andopen the passage by swinging inward as'the air is sucked into the tube,an adjustable set screw for limiting the back swing to a maximum extent,and means for assisting the flow of fuel from the fuel valve consistingof an air tube leading into the mixing chamber on one side of the fuelvalve and adelivery tube leading from the other side of said fuel valvein said mixing chamber to the posterior side of the flap valve in theair tube.

4. An improved carburetor consisting of a right-angledair tube havingvertical and horizontal legs open at one end and adapted for connectionto an intake manifold at the other, a fuel valve assembly upon thehorizontal leg of the air tube, a flap valve in the air tube locatedbeneath the said fuel valve assembly and hinged at its upper edge, alinkbetween said flap valve and the fuel" valve for opening and closingthe fuel valve as the flap valve swings, a butterfly valve in thevertical leg of the air tube operable by the driver, means forrestraining the said flap valve, consisting of a cylinder mountedoutside the said air'tube, a piston within said cylinder whose rod ishinged at its end near the lower edge of the flap valve, said pistonhaving a very small hole formed therein, an adjustable spring in said inthe area. of' the air passage consisting of a weighted flap hinged atits bottom edge in the cylinder, means for altering the suction upon thefuel valve irrespective of the flap valve, consisting of a weighted flapat the back of the flap valve adapted normally to close the air tube andto swing back as the air is sucked past it, and an adjustable set screwadapted to limit the back swing of the weighted flap and enable apredetermined area of air passage.

5. An improved carburetor consisting of a right-angled air tube havingvertical and horizontal legs open at one end and adapted for connectionto an intake manifold at the other, a fuel valve assembly upon thehorizontal leg of the air tube, a flap valve in the air tube locatedbeneath the said fuel valve assembly and hinged at its upper edge, alink between said flap valve and the fuel valve for opening and closingthe fuel valve as the flap valve swings, a butterfly valve in thevertical leg of the air tube operable by the driver, means for enablingvariation in the area of the air passage consisting of a weighted flaphinged at its bottom edge in the bend of the tube and adapted tonormally close the passage and open the passage by swinging inward asthe air is sucked into the tube, an adjustable set screw for limitingthe back swing to a maximum extent, and means for opening the fuel valveto assist in starting up or idling the engine consisting of a depressiontransmitting duct between the airtube above the butterfly valve and thecylinder above the piston.

, WILLIAM JOHNSON.

